Conspiracy theories? Don't get me started...

The High Court fight to the death between The Da Vinci Code and Holy Blood, Holy Grail has made it all the more imperative that anyone who has an extremely interesting conspiracy theory based on historic fact must register it immediately before unpleasantness breaks out further down the line. With that in mind, here are all my amazing, but true, theories. To make it more fun, one of them is false. See if you can guess which one.

The Davina Code Eight members of the royal family are in on the ancient secret that if Davina McCall is ever taken off the telly, the Black Death will return to Britain. A prince breaks ranks and makes the secret public. TV executives decide to take her off anyway, concluding that live coverage of the Black Death would make more interesting telly.

Mars Episcopacy Nasa's Mars Reconnaissance Orbiter photographs the surface of the planet in a fantastically high resolution and beams back clear evidence of traces of bishops. Images of what look like fossilised crooks and mitres are identified close to the surface. President Bush releases a statement saying this proves Christianity was right all along, which is not the same as being anti-Muslim. Arch atheist Richard Dawkins says he has proof that the evidence is forged and was put on Mars by the Roman Catholic church. He claims that the last 14 popes have been using mafia money to fund a series of space missions to Mars to plant false traces of bishops. The Vatican denies this, saying a launchpad unearthed in suburban Rome was to be used for hurling paedophile priests into space.

Private Blood, Private Funding All faith schools in Britain are warmed by human blood being pumped through their central-heating system. The blood is taken from patients booked into foundation hospitals. The only two people who know about this are Tony Blair and Patricia Hewitt, who are actually brother and sister but don't know it, having been separated at birth from their mother, the last of the Mohicans. They were both bathed in privately funded blood when they were born and are rumoured to drink the blood of state-sector employees whenever they can.

They deny this, but it's discovered that all the routes of proposed toll motorways across Britain when seen from above form a Masonic symbol which means 'Drinking the Blood of the Poor and the Sick is Great'. Blair says this is just coincidence, but the journalist who raises the question mysteriously disappears.

Holy Bishop, Holy Balls The current Archbishop of Canterbury carries around with him one of Napoleon's testicles. He is sworn not to reveal where in his body it is actually placed, but everyone in the church has a pretty good idea.

The Brooking Syndrome Trevor Brooking is a direct descendant of Charlemagne, the first Holy Roman Emperor. He was taken from his mother by a group of knights who clothed him in a tracksuit made from elves' guts and placed at the head of a group of 10 other foundlings known to the knights as the Discrete Council of the Chosen Magistrates of Zion but publicly as West Ham United.

Their purpose is to restore the Imperial Reign of Charlemagne the Great, who held dominion over all France, Germany, Spain and the Netherlands, as well as most of eastern Europe. They will do this by infiltrating Uefa's voting committee and pushing through a new set of rules for football.

These will now include a provision that anyone who loses to West Ham United must bow down and swear allegiance to the Chosen Imperius Trevor Brooking. The plan comes unstuck when no team loses to West Ham United.

The Line of the Fop Giles Brandreth is the last surviving descendant of the Pharaohs. Only 100 people know, but none of them thinks it worth mentioning.

Dawn of Blubber The lead singer of Massive Attack has been emitting a high-pitched hum for the past seven years which is summoning the whale population of the world to the Thames. Within 15 years, it will be fully clogged with whale carcasses and these will act as a natural barrier against rising tides after the full onset of global warming.

London will become the last remaining dry bit of western Europe and, like Venice in the 1400s, will become a major, mercantile nation-state powerful enough to take on the might of China. A huge Cockney empire will expand westwards, absorbing Ireland and most of North America, with each member of Massive Attack designated a prince of one of the regions, apart from Andrew Vowles, who left because he disagreed with the artistic direction of the group.

The Copy of the Daughters of Zion As a student at Oxford, David Cameron copied the 1997 New Labour election manifesto off the internet and is now passing it off as his own. Tony Blair eventually takes Cameron to court, claiming plagiarism, but he is himself sued by US Senator Joe Biden of Delaware, who once plagiarised a speech of Neil Kinnock's and is now claiming that he thought of plagiarism first.

Happy Christ, Happy Hitler Christ is still alive and living with Hitler's grand-daughter in Florida. He is a casting director for a small, independent film company that makes animated features about a donkey that gives all its carrots to the poor. Christ has been nominated twice for an award.